Electrical issues? 1982 300sd
 

A few days ago my charge indicator , brake pad wear indicator and brake warning lamp all quit working simultaneously. Then yesterday for what ever reason they all began to work again, but by last night they stopped once again. Is there a common wire or something else these three share? I say three because the glow plug light comes on as it should and even though my highbeam light indicator dosen't work i'm pretty sure I can attribute that to the high beam being inoperable on one side. BTW it's a 1982 300sd.

Alternator
 

1984 300d Turbo
Replace The Alternator Regulator On Back 2 Screws And ($28.00) Or
New Alternator,

These are all affected by the grounding of the alternator. I would check the batt.-chassis and the chassis-engine ground straps first. After that, the alternator is suspect and checking the charging voltage across the battery would give a clue. (I had similar symptoms with an alternator failure.)

I would bet my bottom dollar that its the voltage regulator.Cheap to replace ..
Good luck
Regards
Dan

I did have the battery out the other day. When you say to check the Battery to chassis do you mean I should check to see if the wire that connects to the negative terminal is securely connected to the chassis? And just to be clear, you all agree that either of the suggestions you give would cause all three lights to go?One more thing, I deliver pizza so i'm shutting off and starting my car as well as driving it for about 13 hours while the car was like this. With so many starts (maybe about 50 between yesterday and today) with a bad alternator , wouldn't my battery be totally dead by now? It's showing no signs of weakness concidering my wipers are on constantly , my cd player on all the time as well as my heater.If the alternator was screwed wouldn't my car atleast turn over a little slower by now?

I think I found the problem
 

The cable that goes from the ground on the chassis to the negative post is damaged. The end that clamps on the post with the nut and bolt is broken , so broken now that it's in two pieces. Can this cause the above problems. I never realized but this probibly has something to do with my lights fadeing in and out as well.

yes,you found it replace ground and life will again be good.

Found true problem
 

Turns out the voltage regulator was the problem, i'd say the ground being broken wasn't helping though.Thanks for your help fellers.18 bux at Napa but luckily there was a perfectly good one on the parts car.

You DID fix the ground, right?

I did but I did it before I changed out the regulator so I know the regulator was the cause.Btw it really sucks not being able to shut the car off for 6 hours lol.

after some charging troubles, optimistically replaced the voltage regulator. headed today to pick up a multimeter, saw gremlins in the dash.
the three warning lights (brake warn, park brake, batt) all began flickering intermittently, but in time with each other.
read this thread and went out to reposition the ground wiring a number of ways, but no luck and looks like an intact ground.
the alternator harness looks to be good, and moving that about made no difference.
this was not exactly scientific method kind of troubleshooting, but any ideas where to head next?
going to replace the battery ground cable for fun tommorrow to see if that might have some resolve.

When you get your meter, check your voltage across the battery, while running, in both DC and AC voltage modes and tell us what you find.

done. DC=11.2V AC=23V (analog meter)
increase in rpm has no effect. many thanks.

You have failed diodes in your alternator which is indicated by the high AC voltage. Normally you should have about 12.5-13VDC and less than 1VAC. That explains the flashing in time with each other. Changing the entire unit is recommended as this usually takes out the regulator.

outstanding diagnostics. greatly appreciated.